Authors – Nessan Costello (@NessanCostello), Kevin Deighton (@K_Deighton), Josh Dyson (@Nutrition_JD), Jim McKenna, Ben Jones (@23Benjones)

Associated Research Publications  
  1. Snap-N-Send: A valid and reliable method for assessing the energy intake of elite adolescent athletes –  

  1. Commentary: Snap-N-Send: A Valid and Reliable Method for Assessing the Energy Intake of Elite Adolescent Athletes –  

A good diet can optimise the health, development and performance of athletes. To improve diet practitioners require accurate dietary assessment tools. However, current dietary assessment methods are invalid, unreliable and no longer scientifically acceptable; new and improved methods are required. This article has been written to share a novel behavioural approach and valid dietary assessment method, titled ‘Snap-N-Send’, with both the applied Sport and Exercise Nutrition practitioner/researcher and wider athlete Multi-Disciplinary team.   

The Importance of Assessing the Diet of Athletes 

Both adolescent and senior elite and professional athletes are exposed to distinct training, competition and home-based loads, which result in equally distinctive total energy expenditures (Morehen et al., 2016, Anderson et al., 2017). The accurate identification of energy intake (EI), dietary patterns and nutritional status can help inform service delivery, safeguarding energy availability and therefore optimising the health, development and performance of athletes (Mountjoy et al., 2014).

Challenges of Implementing Accurate Dietary Assessment

For practitioners and researchers it is imperative that any dietary assessment method is both reliable and valid. A method is considered reliable, or precise, when it can consistently reproduce findings. Whereas, a method is considered valid, or accurate, when it can correctly measure what it set out to measure. A valid and reliable dietary assessment tool is important because it reduces both random (is it reliable?) and systematic (Is it valid?) measurement error (Bingham, 1991). Unfortunately, both traditional retro- (dietary assessment tools which assess what you ate in the past i.e. 24-hr dietary recalls, diet histories, food frequency questionnaires) and prospective (dietary assessment tools what assess what you ate in the present i.e. estimated- and weighed food diaries) dietary assessment methods consistently report substantial errors of validity and reliability (Fig 1.) (Archer et al., 2013). Accordingly, the continued use of such limited traditional methods is unacceptable (Dhurandhar et al., 2015); new and improved techniques are warranted  (Thompson et al., 2010).

“Snap-N-Send is a valid and reliable dietary assessment tool when used to assess the energy intake of elite adolescent athletes”
 A Novel Behavioural Approach

To address aforementioned limitations, we propose a novel behavioural approach within improved dietary assessment (Costello et al., 2017b). This approach uniquely splits the source of dietary assessment error into two separate entities; methodological and behavioural error. Methodological error includes any error innate within the design of a dietary assessment tool, whereas behavioural error includes any error caused by incorrect participant adherence to the measurement tool. Unfortunately, only a traditional or contemporary weighed food diary, completed in real-time as designed, has the theoretical potential to be absent of methodological error (Thompson et al., 2015). This is because it adheres to real-time ecological momentary assessment (EMA) principles (Shiffman et al., 2008) and thus does not suffer from common limitations which bias other methods (e.g. recall bias). Despite this, completion of a traditional food diary requires high participant effort and is therefore often completed incorrectly (i.e. via estimation or from memory); introducing behavioural dietary assessment error.

Behavioural error arises from either poor individual ‘capability’ and/or ‘motivation(Grenny et al., 2013) to complete a dietary assessment method exactly as designed for the entirety of the recording period. For example, poor accessibility to weighing scales during training might affect the ‘capability’ of an athlete to accurately weigh what they consumed. Whereas, poor ‘motivation’ to correctly complete a weighed food diary in real-time, may result in its completion from memory many days after item consumption. Clearly, if an individual is not behaviourally adhered (i.e. both ‘capable’ and ‘motivated’) to record their diet correctly for the entirety of the recording period, then they will introduce measurement error of a behavioural origin into the dietary analysis.

“Snap-N-Send demonstrated enhanced validity and reliability over an estimated food diary used in isolation or combined with a 24-hr dietary recall interview”

Figure 1. Sources of behavioural and methodological measurement error

Snap-N-Send: What is it?

Snap-N-Send is a novel dietary assessment tool which utilises smartphone technology (i.e. pictures and WhatsApp) and leading behaviour change science (the Behaviour Change Wheel; Michie et al., 2014) to over-determine successful behavioural adherence to real-time dietary assessment (EMA; Shiffman et al., 2008). At all times, behaviour change techniques (BCTs) are used to motivate, support, reward and incentivize athletes to record their diet in real-time as it occurs for the entirety of the recording period (Michie et al., 2014). The method is as simple as; SNAP-N-SEND (Fig 2.).

Figure 2. Snap-N-Send: how does it work for practitioners and researchers?

 Snap-N-Send: How Did We Validate It?

Snap-N-Send was validated within a randomised, counter-balanced crossover design (Costello et al., 2017a). Participants were asked to record their diet across two 4-day assessment periods, once via an estimated food diary and once via Snap-N-Send. Each four-day assessment included a three-day free-living period and a ten-hour lab-based period, to improve study internal and external validity. Results strongly evidenced the enhanced validity and reliability of Snap-N-Send over the estimated food diary used in isolation or combined with a 24hr dietary recall interview. Findings were replicated across the three-day free-living period, 10-hour lab period and combined four-day period, increasing confidence in the results. Snap-N-Send is currently in the process of being validated against DLW assessed total energy expenditure across longer five and seven day periods.                   


Figure 3. Two 4-day assessment periods with over £3,000 spent on food!

What You Need To Do To Make Snap-N-Send Work! 

Snap-N-Send has been designed to be as simple as possible for the athlete; literally ‘Snap-N-Send’ (see Figure 3). To participate, athletes require a smartphone, the free picture messaging application ‘WhatsApp’, a measurement shaker (ml) and a home-based weighing scales (Figure 4.).

Figure 4. Example of Snap-N-Send with a home weighed meal. Athletes should be encouraged to weigh self-prepared meals when possible to enhance validity.

3 Points to Consider When Using Snap-N-Send:
  1. Provide Each Athlete with A 500ml Measurement Shaker; Shakers provide a quick and convenient way for the athlete to accurately measure fluid consumption and can be kept as reward for accurate method adherence! Athletes are encouraged to weigh home prepared meals e.g. dinner, so if they don’t own a pair of weighing scales provide these for them as well.
  2. Consider ‘If-Then’ Situations; Before starting the dietary assessment period consider all possible occasions, or events, that might occur to prevent the athlete from accurately carrying out ‘Snap-N-Send’. For example, in and around training sessions, matches, periods of poor Wi-Fi connection or a limited mobile data plan. Each of these ‘If-Then’ situations, should then be planned for accordingly so that the athlete has a prepared plan of action they can follow to ensure accurate diet recording during these periods.
  3. Consider All Information; Dietary analysis performed via Snap-N-Send provides the practitioner/researcher with extremely valuable information in excess of absolute energy or dietary intakes. For example, analysis of an athlete’s diet in their habitual environment (EMA; Shiffman et, 2008) provides a wealth of contextual information about what, when and why the athlete consumes the diet they do. This information is invaluable to both the applied practitioner and researcher, for determining how to improve dietary intake or causal factors behind consumption.
Snap-N-Send: What Are The Limitations?

Despite the exciting promise of ‘Snap-N-Send’, no method is without limitation. The dietary analysis relies upon picture-based portion size estimation by the practitioner/researcher. Although more accurate than athlete estimation, this will inevitably introduce some degree of methodological measurement error into the analysis. To minimise this, athletes should be encouraged to weigh items when required (Fig 4.) and the researcher should weigh picture replicated food portions when required.

Fig 5. An example of the data collection process via Snap-N-Send and how it differs for both practitioners and researchers. Practitioners are focused on improving dietary intake whereas researchers are focused on accurately assessing diet.

Conclusion: Can We Now Accurately Assess What Athletes Are Eating?

To conclude, Snap-N-Send is a quick and easy dietary assessment tool which can be effectively implemented by both practitioners and researchers to more accurately assess the dietary intake of athletes. Moreover, Snap-N-Send’s commitment to real-time dietary assessment provides a wealth of contextual knowledge around the behaviours that drive consumption, external lifestyle factors (i.e. sleeping patterns) and a precise assessment of nutritional timing. Although some degree of error is likely to exist in all forms of dietary self-reporting, Snap-N-Send offers new hope that we can accurately assess the dietary intakes of athletes during future assessment.

If you are interested in learning more about Snap-N-Send please feel free to contact Nessan Costello at ‘’.

About the authors:

Nessan CostelloNessan is a SENr accredited performance nutritionist and final year Ph.D. student within the Carnegie Adolescent Rugby Research (CARR) group at Leeds Beckett University. Nessan currently works as a performance nutritionist for Leeds Rhinos RLFC and Queen Ethelburga’s Collegiate.

Josh DysonJosh is the lead performance nutritionist for the Tennis Foundation (GB Wheelchair Tennis) and owns Manchester based nutrition consultancy Nutrition JD. Previous applied experience has been gained with Lancashire County Cricket Club, Sale Sharks Academy, University of Oregon, Seattle Seahawks, Northamptonshire County Cricket Club and Sri Lanka Cricket. Josh holds a masters in Sport & Exercise Nutrition (Leeds Beckett University) and is an accredited SENr Graduate.